Select What to Calculate, then enter the remaining Parameter Values. Optionally, select a parameter to Fast-Forward, and specify number of and increment per iteration.
Press the Default button to use the original default parameter values, or the Undo button to clear modifications made to current defaults.
Press the Calculate button for results.

4.  Power Computations for Designing Comparative Poisson Trials with Unequal Group Sizes [ref: Brown & Green]

 
What to Calculate: Fast Forward: Specify Parameters:  
 
 
  for the two groups (experimental/control):
 
Fast Forward Options: